Central particle removing system for noncylindrical storage facilities



P 30, 1969 J. L. PETERSON 3. 69.7 0

CENTRAL PARTICLE REMOVING SYSTEM FOR NONCYLINDRICAL STORAGE FACILITIESFiled April 18, 1968 5 Sheets-Sheet 1 INVENTOR JOHN L. Pzrmsozv I BY vwan, m4

ATTYS.

Sept. 30, 1969 J. PETERSON CENTRAL PARTICLE REMOVING SYSTEM FORNONCYLINDRICAI. STORAGE FACILITIES 5 Sheets-Sheet 2 Filed April 18, 1968INVENTOR. JOHN L. PETERSON BY I w ll, g 39km.

ATTys.

Sept. 30, 1969 J. L. PETERSO 3,469,720

CENTRAL PARTICLE REMOVING SYSTEM FOR NONCYLINDRICAL STORAGE FACILITIESFiled April 18. 1968 5 Sheets-Sheet 3 J wmm v w I NVENTOR. JOHN L.PETERSON Ara s.

Sept. 30, 1969 P E 3,469,720

CENTRAL, PARTICLE REMOVING SYSTEM FOR NONCYLINDRICAL STORAGE FACILITIES7 Filed April 18, 1968 5 Sheets-Sheet 4 JKSQK 'llll v INVENTOR.

Jomv L. PETERSON L022! it. swim AT' gs.

pt. 30, 1969 J. L. PETERSON 3,46

CENTRAL PARTICLE REMOVING SYSTEM FOR NONCYLINDRICAI. STORAGE FACILITIESFiled April 18, 1968 5 Sheets-Sheet 5 ,6? 9 67 67 68 67 11 73 o I OINVEIVTOR. JOHN L PETERSON Arv gs.

w'glapm 3,469,720 CENTRAL PARTICLE REMOVING SYSTEM FOR NONOYLINDRICALSTORAGE FACILITIES John L. Peterson, Spokane, Wash., assignor to AtlasSpokane, Inc., a corporation of Washington Filed Apr. 18, 1968, Ser. No.722,361 Int. Cl. B65g 65/30 US. Cl. 214-17 7 Claims ABSTRACT OF THEDISCLOSURE The disclosure describes a particle removing and transfersystem mounted in the center of a rectangular storage facility forremoving particles from a particle pile and transferring the particlesto apertures formed in the storage floor. The storage floor has inclinedsurfaces that extend downward from the center to the walls. The transfersystem includes a plurality of drag lines or drag means each having oneend thereof attached to a continuous chain that follows an elongatedpath about a diagonal axis. The drag lines have digging elements mountedthereon for moving against the base of the pile to remove particlestherefrom.

BACKGROUND OF THE INVENTION This invention relates to particle storagefacilities and more particularly to particle storage facilities that arenoncircular in cross sectional and that have transfer systems mounted inthe center of the facility for systematically removing particles from aparticle pile.

Many particle materials such as silage, sawdust, and vermiculite arestored in enclosures in which the particles are irregularly dumpedthrough the top of the enclosure to form a particle pile within theenclosure. Frequently, it is necessary to remove the particles from theenclosure in a systematic and continuous flow. This is particularlyimportant in the case of sawdust that is utilized as a source of fuelfor power generation plants such as those commonly found in lumber,paper and plywood mills. Generally a conveyor system is mounted belowthe floor of the enclosure or storage facility for receiving the sawdustthat falls by gravity through the apertures of the floor. However, overa period of time sawdust has a tendency to form arcs or to bridge overthe apertures in the floor, thereby stopping the flow of sawdust.

To manually break the bridge is costly and dangerous. Several personshave lost their lives attempting to break the bridges that had formed inenclosures. Prior efforts to overcome the difiiculty has been largelydirected towards the use of rigid mechanical digging devices that areeither rotated or extend radially outward from the center of cylindricalstorage facilities as shown in US. Patents 2,755,942 and 2,736,461 orwhich extend diametrically across the pile as shown in US. Patents2,792,- 153 and 2,496,146. In my US. Patent No. 3,011,658, I disclose anapparatus for transferring sawdust from the base of the pile. Theapparatus includes a circular ring circumscribing the base of the pilethat is powered to turn about the center of the support floor. One endof a drag line is connected to the ring and the free end extendsinwardly. As the ring rotates the angular movement of the ring causesthe free end of the drag line to be urged inwardly against the base ofthe sawdust pile to remove sawdust from the pile and to break bridgesthat form in the sawdust pile.

In my copending application Ser. No. 666,614 I provide a particletransferring means for use in non-cylindrical storage facilities. Theapparatus includes a substantially rectangular track that circumscribesa particle States Patent O Patented Sept. 30, 1969 pile. A continuouschain is mounted in the track for pulling one end of a drag line aboutthe inside of the enclosure. The floor of the enclosure has inclinedsurfaces that extend downward from the side walls of the enclosuretowards the center to bias the free end of the drag line toward thecenter of the facility.

One of the principal objects of this invention is to provide a centralparticle transfer means for efliciently, economically and reliablyremoving particles from the base of a particle pile located in anoncylindrical enclosure.

An additional object of this invention is to provide an apparatus forremoving particles from the base of the pile in which the particleremoval apparatus is located substantially in the center of theenclosure.

A further object of this invention is to provide a central particleremoving apparatus for a noncylindrical storage facility that isefficient in removing particles from the pile and is capable ofoperating even through large forces are exerted on digging elements ofthe apparatus.

These and other objects will become apparent upon reading the followingdetailed description of a preferred embodiment of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of thisinvention is illustrated in the accompanying drawings, in which:

FIG. 1 is an elevated prespective view of a storage facility that has anoncircular horizontal cross section;

FIG. 2 is a plan view of the particle storage facility showing aparticle transfer means mounted in the center of the facility for movingthe drag lines over a storage facility floor that has inclined surfacesthat extend from the center of the facility downward to the side wallsof the facility;

FIG. 3 is a vertical cross sectional view taken along line 33 in FIG. 2;

FIG. 4 is a cross sectional view taken along line 4-4 in FIG. 2;

FIG. 5 is a fragmentary side view showing a section of a drive means formoving the drag lines over the floor; and

FIG. 6 is a fragmentary plan view of a section of one of the drag linesshowing digging elements for removing particles from the base of thepile.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring in detail toFIG. 1, there is shown a particle storage facility which is generallydesignated by the arrow 10. The facility has a rectangular horizontalcross section with end walls 11 and 12 and side walls 13 and 14surrounding a floor 20 that supports the particles. The intersection ofthe floor with the end walls and side walls forms corners 15, 16, 17 and18 respectively (FIG. 2). The floor 20 has inclined flat surfaces 21 and22 that slope from a center ridge 23 outwardly toward the side walls andthe corners 16 and 1-8 with the slope of the inclined surfaces 21 and 22being at an acute horizontal angle with the side wall. The center ridge23 extends along a horizontal diagonal axis L of the storage facility.The diagonal axis L is at an acute horizontal angle with respect to theend walls 11 and 12.

The slope of the inclined surfaces 21 and 22 is less than the angle ofrepose of the particle material. For the purpose of illustration only,the slope of the surfaces 21 and 22 is shown at approximately 30. Withthis slope the particles will conform to the sloping floor when dumpedinto the facility.

Elongated cross apertures 25 and 26 are formed in the inclined surfaces21 and 22 respectively for permitting the flow of the particlestherethrough. Elongated end apertures 26 and 27 are formed in the flooralong the center ridge 23 adjacent the end walls respectively forpermitting the flow of particles therethrough. Grating 30 is mounted inthe apertures 25-28 for permitting the flow of particles therethroughwhile providing support for particle removing equipment that moves overthe apertures.

A conveying system is mounted below the floor for receiving theparticles and conveying the particles from the storage facility 10. Theconveying system includes two cross conveyors 32 and 33 mountedimmediately below these apertures 25 and 26 respectively. Crossconveyors 32 and 33 convey the particles upwardly and inwardly towardthe center to a main convceyor 34 that extends the full length of thestorage facility and immediately below the apertures 27 and 28 forconveying the particles from the storage facility.

In cooperation with the inclined surfaces 21 and 22, the storagefacility has a particle transfer system that removes the particles fromthe base of a particle pile supported on the floor and moves theparticles to the apertures 25-28. The particle transfer system includesfour or more drag means 36 that are pulled over the floor by anelongated drive means 37. The drive means 37 is mounted in the center ofthe facility along the center ridge 23. An elongated shield 38 ismounted immediately above the drive means 37 to support a portion of theparticle pile and to prevent the particles from clogging the drivemeans.

The drive mans 37 includes a double link continuous chain 40 (FIG. thatis mounted between a horizontal drive sprocket 41 and a horizontal idlersprocket 42 to form an elongated continuous path along the diagonal axisL. The horizontal drive sprocket 41 is mounted on a vertical drive shaft43 that extends upwardly through the floor 20. The shaft 43 is rotatablysupported by an upper bearing 44 and a lower bearing 45. The bearings 44and 45 are mounted on brackets 46 and 47 respectively as shown in thefragmentary view FIG. 5. The shaft 43 is rotated by a conventional powerdrive with a pulley 48 mounted to the lower end of the shaft.

The horizontal drive sprocket 41 has two spaced sprocket wheels 49 and50 for engaging the space double links of the chain. Each link of thechain is separated by cylindrical spacers 52.

The drag means 36 includes four or more flexible cables 54, 55, 56 and57 that are pivotally attached to the chain 40 at spaced intervals. Theflexible cable 54 is attached to the chain at point 61. The flexiblecable 55 is attached to the chain at point 62. The flexible cable 56 isattached to the chain at point 63 and the flexible cable 57 is attachedto the chain at point 64. A fitting 58 (FIG. 5) is aflixed to one end ofeach flexible cable. The fitting 58 is aflixed to a collar 59 that isrotatably mounted about one of the spacers 52 of the chain.

Digging elements 66 are mounted on each cable adjacent to its free endfor engaging the base of the particle pile and removing particlestherefrom. Each of the digging elements 66 includes a socket 67 (FIG. 6)affixed to the cable. A sleeve 68 is coaxially mounted about the cablewith one end aflixed to the socket 67. An annular abutment 70 is formedabout the outer circumference of the sleeve 68. A digging disc 69 iscoaxially mounted about the sleeve 68 with a hub 72 of the disc engagingthe annular abutment 70 to prevent the axial movement of the hub alongthe sleeve 68. A weighted hook 73 is fixed to the free end of each cableto urge the free end down the inclined surfaces 21 and 22. Each of thehooks 73 are wheel supported to facilitate the movement of the hook downthe inclined surfaces toward the walls.

Each of the flexible cables 54-57 is of a suflicient length so that thecable will extend around at least one end of the elongated path of thecontinuous chain 70 to prevent lateral force being applied to the chainfrom the cable. For example, as shown in FIG. 2 cable 54 is attached tothe chain at point 61. The chain then extends rearward along the side ofthe chain 40 and then around the idler sprocket 42. The flexible cable55 is attached to the chain at point 62 and extends around the drivesprocket 41 and then along the side of the chain and then around theidler sprocket 42. From this description it can be appreciated that thepulling force of the cable is directed tangentially to the chain at thepoint of connection and that each cable extends at least one of thesprockets to provide additional frictional engagement to substain highpulling forces.

To assist the digging elements to move around each end of the elongateddrive means, an annular guide 76 (FIG. 5) is fixed to each of thesprocket shafts. Each of the guides 76 has a conical surface 77 thatprovides a movable surface for supporting the digging elements andcarrying the digging elements around each end of the elongated drivemeans.

During the operation of the facility the particles fed into the particlestorage facility and descending to the floor to form a pile conformingto the shape of the enclosure. The angle of the inclined surface 21 and22 is less than the angle of repose of the particles but is sufficientto bias the free ends of the drag means outwardly toward the walls ofthe facility. The angle of the inclined surfaces 20 and 21 is sufficientto permit the free end of the flexible drag means to slide or rolltoward the side and end walls to bias the discs 69 against the base ofthe pile. As the drag means 36 move over the floor the particles areremoved from the base of the pile and pulled over the aperture 25-28.The drag means work from the inside out to gradually eat into the baseof the pile in a systematic manner for preventing the formation ofbridges over the floor apertures and to provide a constant flow ofparticles onto the conveyor system.

It should be understood that the above described embodiment is simplyillustrative of the principles of this invention and numerous othermodifications may be made without deviating from the principles thereof.Therefore, only the following claims are intended to define myinvention.

What I claim is:

1. A particle storage facility for receiving particles such as sawdustin a pile and for removing the particles from the base of the pile, saidfacility having side walls in combination with the improvement of:

(a) a floor for supporting the pile, said floor having inclined surfacesthat extend outwardly and downwardly from the center to the side wallsat a slope less than the natural angle of repose of the particles toprevent the natural flow of the particles toward the side wall, saidfloor having at least one aperture formed therethrough for permittingthe fiow of particles therethrough;

(b) a particle conveying means below the floor aperture for receivingthe particles and conveying the particles from the storage facility;

(c) elongated drag means slidably mounted on the floor for engaging thebase of the pile; and

(d) a drive means positioned in the highest portion of the floor andconnected to one end of the drag means for moving the drag means overthe floor with the free end of the drag means biased down the inclinedsurfaces by gravity against the base of the pile to remove the particlesfrom the pile and move the particles to the floor aperture and onto theconveyor means for conveyance from the storage facitity.

2. A particle storage facility as defined in claim 1 wherein the drivemeans includes a continuous drive chain that follows an elongated pathwith spaced ends and wherein each drag means is flexible with one endpivotally connected to a segment of the chain.

3. A particle storage facility as defined in claim 2 wherein each dragmeans includes a flexible cable that is of suflicient length to extendabout at least one end of the path of the drive chain.

4. A particle storage facility as defined in claim 1 wherein the storagefacility is substantially rectangular in cross section with end wallsand side walls in which the distance between the side walls is less thanthe distance between the end walls and wherein the slope in the inclinedfloor surfaces is at an acute angle to the side walls and whereinfurther the drive means is elongated and aligned along a horizontaldiagonal line that is at an acute angle to the end walls.

5. A particle storage facility as defined in claim 4 wherein theelongated drive means includes a continuous chain that follows anelongated path about spaced chain sprockets defining two spaced ends ofthe elongated path.

6. A particle storage facility as defined in claim 5 wherein each dragmeans includes a flexible cable connected to a segment of the chain inwhich the cable is of sufficient length to extend around at least oneend of the elongated path at all times to prevent lateral force beingapplied to the chain.

7. A particle storage facility as defined in claim 6 wherein each dragmeans further includes digging elements mounted on the cable adjacentthe free end for engaging the base of the particle pile and wherein thedrive means further includes rotating guides positioned at the ends ofthe elongated path for assisting the movement of the digging elements ofthe drag means around the ends of the elongated path.

References Cited UNITED STATES PATENTS ROBERT G. SHERIDAN, PrimaryExaminer US. Cl. X.R. 222228

